The reasons are: - the blood is very low on nutrition - the leech is not feeding itself regularly
The leech slows it metabolism a lot, so it can survive on very low nutrition. The blood is very low on nutrition, and it is the leech's food source, so the evolution made it preserve energy.
The leach doesn't have the opportunity to feed itself on regular basis, so it takes maximum advantage of any opportunity and consumes as much blood as possible so that it can survive long term when it will not have food at disposal.
Predator Because they are at the top they eat everything so when the arrows point towards them on the web it means they are essentially eating them because like a food web this organism is on top and the other prey are on the bottom
Double-stranded RNA (dsRNA) is RNA with two complementary strands, similar to the DNA found in all cells, but with the replacement of thymine by uracil.
